Hydrocarbon oils containing nu-substituted aminopropylamine monosulfonates



United States Patent 2,989,387 HYDROCARBON OILS CONTAINING'N-SUBSTI- m AMINOPROPYLAMINE MONO SULFO- Henry A. Ambrose and Earl L. Humphrey, Penn Hills Township, Allegheny County, Pa., assignors to Gulf Research & Development Company, Pittsburgh, Pa., a corporation of Delaware No Drawing. Original application Aug. 12, 1954, Ser. No. 449,496. Divided and this application Dec. 12, 1958, Ser. No. 779,806 (Cl. 44-72) 7 Claims.

This invention relates to stable hydrocarbon oil compositions. More particularly, the invention is concerned with the stabilization of hydrocarbon oils by incorporation therein of certain salt compositions.

Various hydrocarbon oils tend .to deposit oil-insoluble deterioration products that are formed during storage or service conditions. For example, straight run distillate fuel oils can form sludge during storage despite their high content of normally stable parafiinic hydrocarbons. Where sludge deposition occurs in suchoils, it is usually attribuated to the presence in the oils of materials that are not normally present, e.g., impurities picked up during refining, or perhaps remaining in the oil due to incomplete refining, rather than to the inherent instability of the oil itself. Sludge formation in straight run fuel oils is considered to be chiefly a problem of oxidation and the formation of insoluble oxygenated products.

Unlike straight run distillate fuel oils, catalytically cracked fuel oil distillates are rich in olefinic, aromatic, and mixed olefinic-aromatic components. Sludging in the latter oils is considered to involve primarily condensation and/or polymerization type reactions which result in the formation of insoluble reaction products of relatively high molecular weight.

Distillate fuel oil compositions containing mixed straight run and catalytically cracked fuel oil distillates have proved especially troublesome with regard to sludge deposition during storage at normal atmospheric temperatures. It has been found that the sluding characteristics of such mixed, or blended, fuel oil distillates are strikingly poor, much poorer than can be accounted for from the known sludging characteristics of the individual component fuel oil distillates alone. While the sludge formed in mixed distillate fuel oils no doubt contains some sludge of the type formed in each component oil, the sludge formed in the blended fuel oils is consistently greatly in excess of the amount that can be accounted for from the known sludging tendencies of the individual component oils, thus indicating the existence of a special problem.

Lubricating oils, such as those used for crankcase lubricants in internal combustion engines of the gasoline or diesel type, present still another, distinct and difierent deposit problem, that is, they tend under service conditions to deposit oil oxidation products, fuel soots, resins and other oil-insoluble deterioration products on the metal surfaces with which the oil comes in contact. These oili-nsoluble deposition products can build up to form sludge and varnish deposits which can in turn interfere with proper lubrication and adversely affect engine operation.

We have found that the deposition of oil-insoluble de terioration products from hydrocarbon oils can be substantially diminished by incorporation therein of minor amounts of the salt compositions of this invention. The salts whose use is included by this invention are the monosulfonates of oil-soluble hydrocarbon sulfonic acids and 1,3-diaminopropanes having the general formula:

ice

- 2 where R is an aliphatic radical containing from 8 to 30 carbon atoms.

The salts whose use is included by this invention are prepared by partial neutralization, with an oil-soluble sulfonic acid, of a 1,3-diaminopropane that contains a long-chain aliphatic radical-substituted, secondary amino grouping. The aforesaid partial neutralization reaction normally takes place spontaneously at room temperature with evolution of heat, but in some cases moderate heating may be desirable in order to accelerate the reaction. In no case should the reaction be carried out at temperatures in excess of about F., since decomposition of the resulting ammonium salt may occur with prolonged exposure to temperatures substantially in excess of this limit. In order to produce the desired monosulfonate salts, the mol ratio of the reactants in the neutralization procedure should be approximately 1:1. In no case should the molar quantity of the sulfonic acid be allowed substantially to exceed that of the diamine, in order to avoid formation of appreciable amounts of undesirable disulfonates.

The diaminopropanes that form monosulfonates whose use is included by this invention may be illustrated by the generic formula:

where R is an aliphatic radical containing from 8 to 30 carbon atoms. Thus, the present invention includes, for example, the use of monosulfonates of long-chain alkyl-, alkenyland alkadienylarninopropylamines. Specific examples of such diamino compounds are 3 octylaminopropylamine, 3 decylaininopropylamine, 3 tetradecylaminopropylamine, 3 tetradecenylaminopropylamine, 3- eicosylaminopropylainine, 3 ei-cosenylaminopropylamine, 3 docosylaminopropylamine, '3 docosenylaminopropylamine, 3 docosodienylaminopropylamine, and 3 triacontanylaminopropylamine. Within the general class of 1,3-diaminopropanes capable of forming the monosulfonates of this invention, the diamines in which the longchain, aliphatic N-substituent of the secondary amino grouping is an alkyl or alkenyl group containing at least 12, and preferably from 12 to 18, carbon atoms are considered to form especially effective addition agents. Examples of 1,3-diarninopropanes which are considered to form exceptionally effective monosulfonates for the purposes of this invention are the 3-dodecyl-, the 3-hexadecylaminopropylarnines, and especially the 18 carbon alkyl-, alkenyl-, and alkadienyl-substituted 1,3-diarnin0- propanes, such as the 3-octadecyl-, 3-octadecenyl-, and 3-octadecadienylaminopropylarnines. Although aliphatic hydrocarbon N-substitutcd 1,3-diarninopropanes are preferred, the invention also includes salts derived from diamines in which the N-substituent of the secondary amino grouping is itself substituted with one or more groups that contain elements such as oxygen, sulfur, nitrogen or halogen and that do not interfere with the oil-solubility of the salt. Representative examples of l,3-diaminopropanes containing such substituents are 3-ricinoleylaminopropylamine and 3 (chlorostearyl) aminopropylamine. Mixtures of 1,3-diaminopropanes such as are formed when the long-chain, aliphatic N-substituent in the secondary amino grouping is derived from mixed fatty acids obtained from naturally occurring fats and oils form highly effective monosulfonate salts within the scope of this invention. In such instances the aliphatic N-substituent in the secondary amino grouping will be a straightchain, monovalent hydrocarbon radical containing from 8 to 20 carbon atoms. Examples of: such mixtures of 1,3 diaminopropanes are 3-tallow-aminopropylamine, 3-soya-aminopropylamine, and 3 -coco-aminopropylamine, where the respective N-substituents are mixed 3 7 alkyl and unsaturated alkyl groups derived from animal tallow (CH-C18) acids, soybean (Cm-C20) acids, and coconut (C C fatty acids.

The sulfoni'c acids that form the mono-sulfonates whose use is included ,by this invention are the oil-soluble hydrocarbon sulfonic acids. Such acids may be represented by the generic formula R SO H, where R is an organic radical of at least predominantly hydrocarbon character which is capable of imparting oil-solubility to the acid. These sulfonic acids may be oil-soluble aliphatic hydro carbon sulfonic acids, including naphthenic hydrocarbon sulfonic acids, representative examples of the former of which are octyl, nonyl, decyl, undecyl, lauryl, tridecyl and myristyl sulfonic acids, and of the latter, the octyl-, dodecyl-, and dodeccnyl-cyclopentyl and similarly substituted cyclohexyl sulfonic acids. Also satisfactory are the alkaryl sulfonic acids such as octyl, decyl, dodecyl and cetyl benzenesulfonic acids, as well as the so-called keryl, or kerosene, and wax-alkyl benzenesulfonic acids, including the corresponding dialkyl benzenesulfonic acids. The preferentially oil-soluble petroleum sulfonic acids, normally referred to as mahogany acids in order to differentiate them from the preferentially water-soluble green acids, are especially suitable for the purposes of this invention. As is well-known in the art, oil-soluble petroleum sulfonic acids may be derived by sulfonation of higher boiling petroleum fractions, normally those having lubricating properties, with conventional sulfonating agents such as oleum, concentrated sulfuric acid, sulfur trioxide, or the like. The oil-soluble sulfonic acids are recoverable from the thus-treated oils by neutralization with aqueous alkali, such as aqueous caustic soda solution, extraction with alcohol or aqueous alcohol, distillation to remove the extraction solvent, and regeneration of the sulfonic acid by treatment of the residue with an equivalent amount of a mineral acid. Particularly suitable mahognay acids are those having an average molecular weight between about 400 and about 650.

The reaction products of the above-described partial neutralization of the long-chain aliphatic N-substituted 1,3-diaminopropanes with substantially equirnolar proportions of oil-soluble hydrocarbon sulfonic acids are simple addition salts having the following probable generic formula:

where R and R are as defined above. Although some product may be formed in which the sulfonic acid adds to the primary amino group, the above-indicated product tends to predominate in view of the greater basicity of the secondary amino group.

Thepreparation of the monosulfonates whose use is included by this invention, previously described in genoral, and a specific embodiment of the invention are illustrated by the following specific example:

EXAMPLE Oil-soluble petroleum sulfonic acids having an average molecular weight of about 430 were prepared by two successive treatments of a commercially obtained mineral oil solution containing about 30 percent of the calcium salt of mahogany acids with 37 to 38 percent hydrochloric acid at 170 to 180 F., and extraction of the acidified product with benzene. The extract was then blown with nitrogen to dry. The calcium petroleum sulfonate employed had a molecular weight of 905 (calculated from the base number of the 30 percent mineral oil concentrate). Typical samples of said concentrate had thefollowingproperties:

Sample A Sample B Base No 13. 32 12. 69 Sulfate Ash 6. 61 6. 12 Percent Calcium. 1. 1. 89 Percent Barlum 0 0 Percent Sulfur. 2.02

Approximately 430 grams (one combining mol) of the oil-soluble petroleum sulfonic acid obtained as described above were dissolved in approximately 1000 grams of oil and 600 grams of benzene, and the resulting solution was added with stirring to 400 grams (one combining mo of mixed 3-fatty alkyland alkenylaminopropylamines containing approximately 80 percent active ingredient. The latter, designated as 3-tallow-aminopropylarnine, had a theoretical molecular weight of 320, a combining weight of approximately 400, and a melting range of approximately 44 to 48 C. The fatty alkyl and alkenyl substituents of the diamine were derived fromanimal tallow fatty acids. Accordingly, the 3-tallo aminopropylamine contained predominantly 3-oleylaminm propylamine, or 3-octadecenylaminopropylamine, together with lesser proportions of 3-hexadecy1- and 3-octadecylaminopropylamines, and small amounts of 3-rnyristyland 3-linoleylaminopropylamines.

The crude product of the foregoing reaction was a mixture of monosulfonates of mahogany acids and 3-C alkyland alkenylaminopropylamines, the predominant component of which mixture was the monosulfonate of mahogany acids and 3-oleylaminopropylamine. After removal of the benzene, the product prepared as indicated contained about 45 percent of the amine salt reaction product in mineral oil and had the following analysis and physical properties:

Gravity, API 26.0 Viscosity, SUV, F. 3682 Sulfur, percent 1.71 Nitrogen, percent 1.31

The product obtained by reacting the undiluted sulfonic acids (obtained by extraction of a 45 weight percent oil concentrate thereof with about 5 volumes of a solvent comprising equal volumes of water and isopropyl alcohol) in the above-indicated mol ratio with 3-ta1lo aminopropylamine was a soft tan grease at room temperature.

The foregoing example indicates the manner and ease of preparation of the monosulfonate salts of this invention and illustrates a specific embodiment of the invention. Other salts whose use is included by this invention can be prepared by reaction of substantially equimolar proportions of other herein disclosed 1,3-diarninopropanes with the foregoing oil-soluble petroleum sulfonic acids, or with other members of the herein disclosed class of oil-soluble hydrocarbon sulfonic acids, in the aboveindieated molecular ratio. 7

The addition of minor amounts of the salts of this invention to mineral oils tending to deposit insoluble deterioration products has been found to diminish the deposition of such materials from the oils. For example, the addition of very small amounts of monosulfonate salts of the foregoing type to distillate fuel oils, such as blended distillate fuel oils containing both straight run and catalytically cracked components, has been found to produce a marked improvement in the sludging tendencies of the oils. Other distillate fuel oils are also improved by the salts of this invention. In addition, lubricating oils con taining minor amounts of the salts of this invention exhibit substantially reduced tendencies toward deposition of deterioration products.

Naturally, the various monosulfonates of the herein disclosed class do not possess exactly identical eifectiveness, and the most advantageous concentration for each such monosulfonate will depend to some extent upon the particular compound used. Also, the minimum eflective inhibitor concentration can vary considerably according to the specific nature of the oil to be inhibited. In gencral, however, the herein disclosed salts are useful in concentrations of as little as about 0.005 percent to about 25 percent by weight of the composition. Thus, major improveme'nt of the sludging characteristics of distillate fuel oils isusually obtainable by incorporation therein of from about 0.01. toabout 0.05-percent by weight of the herein disclosed class of monosulfonates. Nevertheless, in some casesit will be advantageous to add as much as about 0.1 percent; by weight of the inhibitor, and in unusual instances it may befound desirable to add as much as about 1.0. percent by weight of the inhibitor. The salts of this invention are important in lubricating oils in concentrations of from about 1 to about 25 percent by weight of the composition. Normally major improvement in detergency properties is obtainable by the use of between about 5 percent and about percent by weight of the composition. In the instance of-heavy-duty type oils,

larger amounts, e.g., up to percent by weight of-the composition, can be used.

The monosulfonate inhibitors whose use is included by this invention can be incorporated in the oils to be inhibit'ed in any suitable manner. Thus, the salts can be formed in situ in the oil, they can be added, per se, di-

rectly to the oil,-or they can be added in the form of concentrates. In the case ofa blended fuel oil they can be added either immediately after blending or after the mixture has been stored for a substantial period of time. Alternatively, the salts of this invention can be formed in situ in, oradded per se or in the form of concentrated solutions to one component of the blend, e;g.; either the straight run or the catalytically cracked fuel oil distillate, prior to blending. Suitable concentrates containingthe monosulfonate inhibitors of this invention comprise, for example, mineral oil solutions or dispersions containing from about 2 to 50 percent, and preferably from about BOto 50 percent, active ingredient In the case of mineral oil dispersions it may be desirable to heat the dispersion and/or the oil that is to be inhibited, e.g., to a temperature of from about 100 to about 140 F., in order to facilitate blending. An alternate practice involves blending at ordinary atmospheric temperatures, using a solution of the inhibitor in a solvent that has a large solubility therefor, e.g., benzene, isopropanol or methyl isobutyl ketone, and that does not adverselvaffect the stability of the oil.

As indicated, the salts disclosed herein are adapted to improve the stability of a variety of oils. The class of P distillate fuel oils to which this invention is applicable includes those containing straight run and/or oatalytical- 1y cracked fuel oil distillates such as are used for do mestic heating and for some-industrial heating purposes, typical of which are the so-called No. 2 fuel oils, i.e., distillate oils boiling within the approximate range of 350 to 750 F. and having a minimum API gravity of about 26. The invention is especially valuable in instances where a catalytically cracked fuel oil distillate or solvent treated. The invention is especially important in the improvement of lubricating oils that are adapted for use as crankcase lubricants.

The utility of the herein disclosed class of monosulfonate salts of long-chain, aliphatic N-substituted 1,3-diaminopropanes has been demonstrated by subjecting various mineral oil compositions containing the same to standard'test procedures designed to evaluate various characteristics of the oils. For example, mixtures of catalytically cracked and straight run fuel oil distillates containing various concentrations-of representative salts of the class whose use is included by the invention-have been subjected to a standard accelerated stability test. The test sampleswere made up by adding the desired concentration of eachadditive to be tested to separate samples of various fuel oil mixtures containing 50 percent by volume of a strainght run No.2 fuel oil distillate and 50 percent by volume of a catalytically cracked fuel oil distillate, and having varying sludging characteristics.

The stability test referred to above was carried out on the mixed fuel oil compositions by heating 600 gram samples of the fuel oil compositions for a period of 16 hours at 210 -F. in loosely'stoppered, one-quart clear glass bottles. Following the heating period each test sample was cooled to roomtemperature and filtered by suction through a tared, medium porosity, fritted glass Goooh-type crucible. The sludge in each crucible was washed with heptane. Complete removal of the sludge adhering to the inside of the bottles was obtained by means of a rubber policeman and heptane. The respective crucibles were dried in an oven maintained at 210 F. for 1 hour, cooled in a desiccator and reweighed. The increase in weight was recorded as milligrams of sludge per 600 grams of oil.

The effectiveness of the herein disclosed class of monosulfonates to improve the sludging characteristics of distillate fuel oils is considered to be peculiar thereto and is demonstrated by the fact that corresponding disulfonate salts of the herein disclosed long-chain, aliphatic N-substi-. tuted 1,3-diaminopropanes and sulfonates of low molecular weight 1,3-diaminopropanes do not as a class exhibit appreciable sludge inhibition in distillate fuel oils. Similarly, no appreciable inhibition of sludge deposition in distillate fuel oils is obtained with monosulfonates of non oil-soluble hydrocarbon sulfonic acids and long-chain, aliphatic N-substituted 1,3-diaminopropanes.

As illustrating the improvement obtainable with the class of monosulfonates whose use is included by this invention and also by way of illustrating the unique nature of the properties of these compounds, the specific results obtained by testing fuel oil compositions containing the following additives are set forth in tabular form elsewhere hereinafter: 3-tal1oW-aminopropylamine mono-petroleurn sulfonate (prepared in accordance with the foregoing specific example), 3 tallow aminopropylamine di-petroleum sulfonate (prepared by reacting the diamine and the petroleum sulfonic acid of the example in a 1:2 mol ratio), 3-laurylam-inopropylamine di-petroleum sulfonate (prepared by reacting 3-laurylaminopropylamine and the petroleum sulfonic acid of the example in a 1:2 mol ratio), 3-tallow-aminopropylamine mono-toluene sulfoand a straight run fuel oil distillate are combined in such proportions as to cause a substantial, deleterious effect of the kind previously described. Thus, the invention is important when the ratio of the volume of thecatalytically' cracked to the straight run oil is within the range of about 9:1 and about 1:9. It is especially advantageous when applied to mixed oils containing these oils in a volume ratio within the range of 4:1 and 1:4.

Lubricating oils that arebenefited by the salts of this invention include those derived from Coastal, Mid-Continent and Pennsylvania-type crudes, whether acid treated 2 fuel oil distillates and had the following physical prop- 'erties: i

The foregoing properties are typical of, although not necessarily identical with, similarly compounded Blends B, C, and E, and more complex Blend D.

Table A Sludge, mg./600 g Oil, After 16 Hrs.

1. Blend A-50/50 (V01) Mixture of Mid-Continent S.R.

and F.C.O. No. 2 Fuel Oil Distillate 35.8

2. Blend A plus 0.02 Vol. Percent 3-Tallow"-am1nopropylamine Mono-Petroleum sulfonate 2. 8

3. Blend A plus 0.02 Vol. Percent 3-Tallow"-aminopropylamine Di-Petroleum Sulfonate 74.0

4. Blend A plus 0.04 Vol. Percent 3-Tallow"-aminopropylarnine "Di-Petroleum sulfonate 84. 6

5. Blend B50/50 (Vol.) Mixture of E.V.S.R. and F.0.0.

No. 2 Fuel Oil Distillate 14.0

6. Blend B plus 0.02 Wt. Percent 3-Tallow"-aminopropylamlne Mono-Petroleum sulfonate 1. 7

7. Blend (3-50/50 (V 01.) Mixture of E.V.S.R. and F.O.C.

N o. 2 Fuel 011 Distillate 16.3

8. Blend plus 0.02 Vol. Percent 3-Laurylamiuopropylamine Di-Petroleum Sulionate 16. 4

9. Blend 0 plus 0.03 Vol. Percent 3-Laurylamiuopropylamine Di-Petroleum sulfonate 23. 3

10. Blend D-Mixture of is W.T.S.R./%S.L.S.R.l%

F.O.C. No. 2 Fuel Oil Distillate 1 7. 2

11. Blend D plus 0.02 Wt. Percent 3-Tallow-aminoproylamine Mona-Toluene sulfonate 98. 6

12. Bl nd E50/50 (Vol.) Mixture of Mid-Continent S.R.

and F.0.0. No. 2 Fuel Oil Distillate 18.0

13. Blend E plus 0.02 Vol. Percent 3-Isopropylaminopropylamine Monosulfonate 70. 3

14. Blend E plus 0.02 Vol. Percent B-Isopropylamlnoproylamine Disulionate 62. 4

15. B end E plus 0.02 Vol. Percent Diethylaminopropylamine Monosulfonate 43. 4

16. Blend E plue 0.02 Vol. Percent Diethylaminopropylamine Disulfonate 64.1

, 1 Blend of 33.33 vol. percent each of West Texas straight run, Southern Louisiana straight run, and fluid catalytically cracked No. 2 fuel oil distillates.

Fuel oil compositions 2 and 6 in the foregoing table and the inhibitors used therein are specific embodiments of the invention, and the results shown in the table for these compositions are considered typical of those obtainable with the monosulfonate salts of the class included by the invention. Comparison of the results obtained for Compositions 2 and 6 with corresponding blank Compositions 1 and clearly indicates the marked improvement in sludging characteristics of mixed distillate fuel oils that is obtainable with the salts included by this invention. On the other hand, comparison of the sludging characteristics of Compositions 3 and 4 and Compositions 8 and 9 with those for the respective blank Compositions 1 and 7 indicates that the corresponding disulfonate salts do not as a class function similarly as the monosulfonates included by this invention. Similarly, comparison of the results obtained for Composition 11 with those obtained with blank Composition clearly indicates that monosulfonate salts of non-oilsoluble hydrocarbon sulfonic acids also fail to improve the sludging characteristics of mixed catalytically cracked and straightrun fuel oils. Comparison of thesludging characteristics for Compositions 13 to 16, inclusive, with those for blank Composition 12 indicates that low molecular weight 1,3-diaminopropane sulfonates are unsatisfactoryrinhibitors.

The addition agents of this invention are especially advantageous in that they are essentially ashless in character.vv .ilt will be understood that the foregoing examples of the invention are merely illustrative and that other members of the class of sludge-inhibiting salts whose use is included by the invention can be used in the same concentrations, or in other concentrations within the herein disclosed ranges, to prepare mixed catalytically cracked and straight run fuel oil compositions having similarly improved sludging characteristics. Specific examples of other monosulfonate salts that are suitable for the purposes of this invention are the mono-lauryl sulfonates, mono-myristyl sulfonates, mono-dodecyclcyclohexyl sul fonates, mono-naphthenyl sulfonates, mono-dodecylbenzene sulfonates, mono-cetylbenzene sulfonates, monokerosene-alkylbenzene sulfonates and mono-wax-alkylbenzene sulfonates of 3-dodecylaminopropylamine, 3- tetradecylaminopropylamine, 3'-hexadecylaminopropyl amine, 3-octadecylaminopropylamine and 3-octadecenylaminopropylamine. Other specific examples of suitable additive agents included by the invention are monosulfonates corresponding to those listed above of mixed fatty alkyland alkenylaminopropylamines such as 3- tallow-aminopropylamine, 3-coco-aminopropylamine and 3-soya-aminopropylamine. The foregoing additives can be substituted in the fuel oil composition exemplified by Compositions 2 and 6 in the same or equivalent proportions with beneficial results. Examples of other fuel oil blends are those containing catalytically cracked and straight run distillates in the volume proportions 1:9, 1:4, 4:1, 9:1. The above-listed compounds can be added to these blends in the proportions disclosed, for example, 0.01, 0.02, 0.03, 0.04, and 0.05 percent by weight, with good results.

The monosulfonates of this invention also inhibit deposition of oil-insoluble deterioration products from other hydrocarbon oils. For example, a solvent refined lubricating oil derived from a Mid-Continent crude oil and having a viscosity of about 450 S.U.S. at F. was compared with a sample of the same oil containing 10.0 percent by weight of 3-tallow-aminopropylamine monopetroleum sulfonate prepared in accordance with the procedure of the foregoing example, and with another sample of the same oil containing 12.7 weight percent of 3-tallow-aminopropylamine di-petroleum sulfonate. 'Ihe sulfonates tested were in the form of oil concentrates, and the monosulfonate concentrate had the following inspection:

Acid number 31.30 Sulfur, percent 1.73 Nitrogen, percent 1.28

The inspection data for the base oil and for the oil sample containing the specific monosulfonate mentioned The oil containing the above-indicated monoand disulfonates were subjected to single cylinder Lauson (diesel procedure) engine tests. The tests were carried out in the standard Lauson Model H-2 single cylinder, liquid cooled, four cycle gasoline engine under the following conditions:

This test consists of a series of 24 hour runs continued for a total of 216 hours unless ring sticking or excessive piston deposits warrant stopping the test earlier. The oil is rated on the following basis:

(1) Piston varnish rating in which the piston is compared to a set of standard pistons and visually classified. The rating ranges from 10 for a completely clean piston to for a heavily varnished and lacquered piston.

(2) Number of stuck rings.

(3) Merit rating which is a visual rating and consists of evaluating over-all engine cleanliness and takes into consideration the following factors: ring sticking, oilring plugging, and piston skirt deposits. A merit rating of 100 is perfect (no stuck or plugged rings, no piston skirt deposits).

The results of the test oils are shown below together with the results obtained with a typical sample of the uninhibited base oil:

Table B Piston No. Merit Hours Varnish Stuck Rating Rating Rings 24 1+ 0 62 1. Base 011 48 1 1 57 2g 10 0 100 2. Base on plus 10.0 Wt. Percent 3- 72 "6 Tallow aminopropylamine 96 Mono-Petroleum Sultanate. 9 0 60 168 ""BQ "i 3. Base 011 plus 12.7 Wt. Percent 3- 24 9+ 0 98 Tallow amlnopropylamlne 48 4+ 0 73 Di-Petroleum Sulfonate.

1 Test stopped because of poor piston varnish rating.

Composition 2 in the foregoing Table B is a specific embodiment of the invention, and the results obtained therewith are considered typical of those obtainable with other lubricating oil compositions within the scope of the invention. Comparison of the test results for Compositions l and 2 of the foregoing table illustrates the improvement obtainable with the salts of this invention. Comparison of the test results for Compositions 2 and 3 in the foregoing table shows that the advantageous properties of the salts of this invention are peculiar to the monosulfonates.

The foregoing embodiment of the invention is illustrative; other of the monosulfonate salts of this invention can be substituted in the foregoing lubricant composition in the same or equivalent concentrations with beneficial results. Examples of other compositions included by the invention are lubricating oils containing from 1 to 25 percent by weight of the composition, e.g., 5, 10, 15, 20 percent, of the mono-lauryl sulfonates, mono-myristyl sulfonates, mono-dodecylcyclohexyl sulfonates, mono-naphthenyl sulfonates, mono-dodecylben- Zene sulfonates, mono-cetylbenzene sulfonates, monokerosene-alkylbenzene sulfonates of 3-dodecylaminopropylamine, 3-tetradecylaminopropylamine, 3-hexadecyl- V l0 aminopropylamine, 3-octadecylaminopropylafiiine and 3- octadecenylaminopropylamine. It will be understood that the oil compositions of this invention may contain, in addition to the additives dis closed herein, other improvement agents adapted toimprove the oils in one or more respects. For example, the stable fuel oil compositions .of this invention may contain additionally oxidation inhibitors, flash point control agents, corrosion inhibitors, antifoam agents, ignition quality improvers, combustion improvers and other additives adapted to improve the oils in one or more re spects. The lubricating oil compositions of this invention may contain additionally, for example, antioxidants, detergents, pour point improvers, viscosity index improvers, thickeners, corrosion inhibitors, antifoam agents and other additives for improving the properties of the oil.

It will be apparent to those skilled in the art that many variations of the invention may be resorted to without departing from the spirit thereof. Accordingly, only such limitations should be imposed as areindicated in the claims appended hereto.

This is a division of application Serial No. 449,496, filed August 12, 1954.

We claim:

1. A hydrocarbon oil composition comprising a major proportion of a hydrocarbon oil tending to deposit oilinsoluble deterioration products and a small amount of a monosulfonate of an oil-soluble hydrocarbon sulfonic acid and a 1,3-diaminopropane having the general formula:

where R is an aliphatic hydrocarbon radical containing from 8 to 30 carbon atoms, said small amount being sufiicient to inhibit the deposition of insoluble deterioration products from said oil.

2. The hydrocarbon oil composition of claim 1 where the hydrocarbon oil is a lubricating oil.

3. A fuel oil composition comprising a major proportion of a mixture of straight run and catalytically cracked distillate fuel oils tending to deposit sludge and containing a small amount of a monosulfonate of an oil-soluble hydrocarbon sulfonic acid and a 1,3-diaminopropane having the general formula:

where R is an aliphatic hydrocarbon radical containing from 8 to 30 carbon atoms, said small amount being sufiicient to inhibit sludge deposition from said mixture of oils.

4. The fuel oil composition of claim 3 wherein said small amount is between about 0.005 and about 1.0 percent by weight of said mixture of oils.

5. A fuel oil composition comprising a major proportion of a mixture of straight run and catalytically cracked distillate fuel oils tending to deposit sludge and containing a small amount of a monosulfonate of an oil-soluble petroleum sulfonic acid and a 1,3-diaminopropane selected from the group consisting of 3-alkyland 3-alkenylaminopropylamines wherein the alkyl and alkenyl substituents contain from 12 to 18 carbon atoms, said small amount being suificient to inhibit sludge deposition from said mixture of oils.

6. A fuel oil composition comprising a major proportion of a mixture of straight run and catalytically cracked distillate fuel oils tending to deposit sludge and containing a small amount of the monosulfonate of oil-soluble petroleum sulfonic acids and 3-oleylaminopropylamine, said small amount being sufficient to inhibit sludge deposition from said mixture of oils.

7. A fuel oil composition comprising a major proportion of a mixture of straight run and catalytically cracked distillate fuel oils tending to deposit sludge and containing a small amount of the monosulfonate of oil-soluble petroleum sulfonic acids and mixed 3-a1ky1- and 3-alkenylaminopropylamines wherein said alkyl and alkenyl substituents contain from 14 to 18 carbon atoms, said small amount being suflicient to inhibit sludge deposition from said mixture of oils.

References Cited in the file of this patent UNITED STATES PATENTS Zimmer et al Ian. 15, 1952 Caron et al. July 20, 1954 Stuart et a1. Aug. 7, 1956 Wilson Apr. 22, 1958 Lindberg Apr. 14, 1959 

1. A HYDROCARBON OIL COMPOSITION COMPRISING A MAJOR PROPORTION OF A HYDROCARBON OIL TENDING TO DEPOSIT OILINSOLUBLE DETERIORATION PRODUCTS AND A SMALL AMOUNT OF A MONOSULFONATE OF AN OIL-SOLUBLE HYDROCARBON SULFONIC ACID AND A 1,3-DIAMINOPROPANE HAVING THE GENERAL FORMULA: 